Antineoplaston Therapy in Treating Patients With Neuroendocrine Tumor That Is Metastatic or Unlikely to Respond to Surgery or Radiation Therapy

DISEASE CHARACTERISTICS:

* Histologically confirmed incurable neuroendocrine tumor that is unlikely to respond to existing therapy, meeting 1 of the following criteria:
* Metastatic disease
* Disease that is not curable with surgery or radiotherapy
* Measurable disease by MRI or CT scan
* Tumor must be at least 2 cm

PATIENT CHARACTERISTICS:

Age:

* 18 and over

Performance status:

* Karnofsky 60-100%

Life expectancy:

* At least 2 months

Hematopoietic:

* WBC at least 2,000/mm\^3
* Platelet count at least 50,000/mm\^3

Hepatic:

* No hepatic insufficiency
* Bilirubin no greater than 2.5 mg/dL
* SGOT and SGPT no greater than 5 times upper limit of normal

Renal:

* No renal insufficiency
* Creatinine no greater than 2.5 mg/dL
* No history of renal conditions that contraindicate high dosages of sodium

Cardiovascular:

* No uncontrolled hypertension
* No history of congestive heart failure
* No history of other cardiovascular conditions that contraindicate high dosages of sodium

Pulmonary:

* No serious lung disease, such as chronic obstructive pulmonary disease

Other:

* Not pregnant or nursing
* Fertile patients must use effective contraception during and for 4 weeks after study participation
* No active infection
* No concurrent nonmalignant systemic disease
* Not a high medical or psychiatric risk

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* At least 4 weeks since prior immunotherapy
* No concurrent immunomodulating agents

Chemotherapy:

* At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas)

Endocrine therapy:

* Concurrent corticosteroids allowed

Radiotherapy:

* At least 8 weeks since prior radiotherapy

Surgery:

* Recovered from prior surgery

Other:

* Prior cytodifferentiating agents allowed
* No prior antineoplastons
* No other concurrent antineoplastic agents